There are a wide variety of structural environments having need for a simple highly reliable sealing gasket installable in an expansion joint between adjacent components of a structure. Among these is the expansion void customarily provided between wooden flooring and the adjacent sidewall and sometimes present in tile, marble or terrazo flooring. In the case of hardwood flooring, the sealing expedient must compensate for very substantial expansion and contraction occasioned by varying moisture content. Many proposals have been made heretofore for sealing strips and expedients intended to meet these and other operating requirements. Typical of these are the seals disclosed in the U.S. Patents to Marble U.S. Pat. No. 2,016,968; Irwin U.S. Pat. No. 2,230,688; Tudor-Pole U.S. Pat. No. 3,378,973; Tennison U.S. Pat. No. 3,508,369 and Smith U.S. Pat. No. 3,604,149. Each of these prior teachings is subject to certain disadvantages including the need for bonding or cementitious materials to anchor them in place, or for interlocking engagement with metallic keepers or for reliance upon frictional restraining means. One self-gripping seal design proposes a plurality of relatively long legs flaring outwardly from the opposite sides of the main body of the seal and having wiping contact with the adjacent sidewall of the void being sealed. However, these legs are relatively long, are designed to flex toward one another in the same direction during installation and lack provision for placing the main body in compression transversely of the sealing strip.